Hyperfine structure investigations in the configuration 4f125d6s2 of Tm I by laser-atomic-beam spectroscopy

High resolution laser-atomic-beam spectroscopy has been applied to study the hyperfine structure of transitions starting from metastable states of the configuration 4f125d6s2 of Tm I. Precise values for the hyperfine constants of 8 levels belonging to the configuration 4f125d6s2 and 9 levels belonging to excited odd levels have been determined.